Date: Tue, 23 Apr 2002 10:54:26 -0700 From: Terry Lambert <tlambert2@mindspring.com> To: obrien@FreeBSD.ORG Cc: Danny Braniss <danny@cs.huji.ac.il>, Freebsd Current <current@FreeBSD.ORG> Subject: Re: FreeBSD 5.0 Developer Preview #1 Now Available / diskless booting Message-ID: <3CC59FD2.4846FE32@mindspring.com> References: <obrien@FreeBSD.ORG> <E16ztee-0002kl-00@cs.huji.ac.il> <20020422234701.A52794@dragon.nuxi.com> <3CC539C3.6A1B0281@mindspring.com> <20020423075148.I52794@dragon.nuxi.com>
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David O'Brien wrote: > > > The very original "solution" was to mount NFS / RW. The move to > > > /conf/default/etc was someone's special needs leaking into the FreeBSD > > > repository. If you want to special case, things be my guest -- add an > > > elif test; but leave RW NFS mounted / alone. > > > > This isn't just about NFS... it's also about Fash devices, which > > are only warranteed for a limited number of writes, which mounting > > R/W would really eat into, and it's for read-only media, like in > > the "ClosedBSD" and "PicoBSD" FreeBSD based firewalls, I think. > > As I said Terry, change the patch to not take away RW /. > Add an elif check, add a `readonly_root' rc.conf knob, etc... > But people should stop assuming everyone wants their special needs and > local weirdness. In my experience, the read/write NFS / mount requires that you seriously limit the number of client machines, to get any performance at all. I understand that this is the way that the old SunOS 4.1.3u2 based engineering environments used to be recommended to be configured by the green-and-which Systeam Adminstrator's Guide for SunOS. I would argue that this is not really appropriate for a cluster or other common use today. So if your argument is based on "make no assumptions", it's OK, but you seem to be repeating the mantra "assume the default most common use is like the old SunOS 4.1.3u2 recommended use for a small number of IPC boxes". I think the default should be a read-only /, and if there is a knob, it's to make the / read/write. In SunOS diskless/dataless configurations, as installed off CDROM, the intent of a read/write / was to permit local files to be modified... specifically, /tmp and /etc/hosts and the default configuration data for the ethernet. This was really a desirable (at the time) side effect (IMO), with the real intent being to provide a root image that was customized for the hardware being booted. With the prevalence of kernel modules to support the range of hardware on differently configured diskless/dataless workstations, it really makes much more sense to share a single / image among a lot of machines. If the intent isn't NFS mounting, but local read-only/read-mostly media (which I would argue is a better match for todays common usage), then really you want it to be the default. If that isn't enough: you aren't going to be able to set the knob to make it read-only, after the fact, but setting a knob to make it read/write after the fact is really easy, so it should use negative logic for the feature, anyway. 8-). -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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